The present invention relates to a method of manufacturing a semiconductor laser for communication, a semiconductor laser for communication and an optical transmission module, and more particularly to a method of manufacturing a semiconductor laser for communication with excellent reliability, a semiconductor laser for communication and an optical transmission module.
As represented by a bathtub curve shown in FIG. 1, the failure mode of a product is generally classified into three types, namely an initial failure, a random failure, and a wear-out failure. The meaning of performing a screening test is to remove initial failure products of a semiconductor laser in short times, and to input products in a state of having a sufficiently long expected life into the market.
As the screening test for eliminating initial failure products of a semiconductor laser for optical communication, it is generally used a test of high temperature and large current, which is performed under conditions of 60° C. to 150° C. and 100 mA to 200 mA. An example of such a screening test is described in JP-A No. Hei 10 (1998)-303496.
In R. Paoletti et al., “Highly reliable and high yield 1300 nm InGaAlAs directly modulated ridge Fabry-Perot lasers, operating at 100 Gb/s, up to 110° C. with constant current swing”, PDP 15, OFC 2005, there are described InGaAlAs directly modulated lasers of Fabry-Perot structure operating at up to high temperatures.